甚至于【shènzhìyú】

甚至于 means the same as 甚至, "even", and goes in the same places. The extra 于 makes it a little heavier and more emphatic, and it is most at home at the head of the last clause, where the situation reaches its extreme.

Like 甚至, it often brings in 连…都 or 连…也 to mark the extreme case.

It can also follow 不仅 or 不但 in the second half.

甚至于 or 至于

至于 on its own is a different word. It means "as for" and changes the topic. Dropping 甚 turns "even" into "as for".

• × 他高兴得跳了起来，至于忘了自己在图书馆 → 他高兴得跳了起来，甚至于忘了自己在图书馆

The plain 甚至 has its own point; anything said there about word order applies here too.